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Tracking Issue for function delegation (fn_delegation, RFC 3530) #118212
Description
This is a tracking issue for the RFC "Implement function delegation in rustc" (rust-lang/rfcs#3530).
The feature gate for the issue is #![feature(fn_delegation)].
The feature was accepted for experimentation in #117978 (comment).
About tracking issues
Tracking issues are used to record the overall progress of implementation.
They are also used as hubs connecting to other relevant issues, e.g., bugs or open design questions.
A tracking issue is however not meant for large scale discussion, questions, or bug reports about a feature.
Instead, open a dedicated issue for the specific matter and add the relevant feature gate label.
Steps
- Implement the RFC (roughly in the order of priority)
- Delegation implementation: step 1 #118947 Parse syntax and implement basic desugaring
- delegation: Support renaming, and async, const, extern "ABI" and C-variadic functions #122500 Support renaming
- delegation: Support renaming, and async, const, extern "ABI" and C-variadic functions #122500 Support modifiers like
const,extern,async - delegation: Implement list delegation #123413 Support list delegation (design)
- delegation: Implement glob delegation #124135 Support glob delegation and overriding it with explicit definitions (design)
- Delegation: support coercion for target expression #126699 Support autoref/deref and coercions for the first argument (design)
- Support inheriting generic parameters (design)
- Support providing generic arguments (design)
- Add implicit
#[inline]unless specified otherwise- Add inline attribute to generated delegation function if needed #149763
- Consider whether some selected attributes need to be inherited
-
Selftype mapping (in RFC) - Conversions for arguments and return value in the generated body (in RFC 1, in RFC 2)
- Delegation for associated constants and types
- Support
impl Traitin traits
- Support
- One line sugar for glob-delegating a whole trait impl
- Support recursive delegation (delegation items referring to other local delegation items)
- Support type-relative paths (old prototype)
- Infer delegation target from the target expr instead of using an explicit path (in RFC)
- Adjust documentation (see instructions on rustc-dev-guide)
- Formatting for new syntax has been added to the Style Guide (nightly-style-procedure)
- Stabilization PR (see instructions on rustc-dev-guide)
Unresolved Questions
Many of them in the RFC draft.
Implementation history
https://github.com/rust-lang/rust/pulls?q=is%3Apr+label%3AF-fn_delegation
Reacted by Felipe S. S. Schneider, Robsdedude, Ugrik George, musjj, Thomas McGuire, Shahriar Heidrich, Valeriy Sakharov, Lukas Wirth, Rostyslav Lesovyi, Hasan Mohsin and 12 more
Reacted by jasper310899, Gerard Ruiz, Spirit of Star and Luca Spinazzola
Reacted by jasper310899, Patryk Wychowaniec, Spirit of Star and Rami
Activity
petrochenkov commentedon Nov 23, 2023
cc @Bryanskiy
Auto merge of rust-lang#118947 - Bryanskiy:delegStep1, r=<try>
Rollup merge of rust-lang#118947 - Bryanskiy:delegStep1, r=petrochenk…
Auto merge of rust-lang#118947 - Bryanskiy:delegStep1, r=petrochenkov…
Auto merge of rust-lang#118947 - Bryanskiy:delegStep1, r=petrochenkov…
Auto merge of rust-lang#118947 - Bryanskiy:delegStep1, r=petrochenkov…
Auto merge of #118947 - Bryanskiy:delegStep1, r=petrochenkov,lcnr
Auto merge of #118947 - Bryanskiy:delegStep1, r=petrochenkov,lcnr
Rollup merge of rust-lang#122500 - petrochenkov:deleg, r=fmease
Rollup merge of rust-lang#122500 - petrochenkov:deleg, r=fmease
Auto merge of rust-lang#122500 - petrochenkov:deleg, r=fmease
Auto merge of #122500 - petrochenkov:deleg, r=fmease
254 remaining items
Rollup merge of rust-lang#161866 - aerooneqq:delegation-tests-for-def…
Unrolled build for #161866 in rollup 161906
Rollup merge of #161665 - aerooneqq:delegation-inh-impl-tests, r=petr…
Rollup merge of rust-lang#163798 - paradoxicalguy:delegation-const-cl…
Unrolled build for #163798 in rollup 164230
Rollup merge of rust-lang#164208 - aerooneqq:delegation-wrapping-fiel…
Unrolled build for #164208 in rollup 164322
Rollup merge of rust-lang#164210 - aerooneqq:make-delegation-complete…
Unrolled build for #164210 in rollup 164355
Rollup merge of rust-lang#164361 - aerooneqq:delegation-map-return-wh…
Rollup merge of rust-lang#164361 - aerooneqq:delegation-map-return-wh…
Rollup merge of rust-lang#164361 - aerooneqq:delegation-map-return-wh…
Rollup merge of #164208 - aerooneqq:delegation-wrapping-field, r=petr…
Rollup merge of rust-lang#164361 - aerooneqq:delegation-map-return-wh…
Unrolled build for #164361 in rollup 164418